Nibbling machine



Jan. 7, 1941. G. AKERLIND 2,227,775

NIBBLING MAG'HINE Filed May 31, I938 Patented Jan. 7, 1941 UNITED STATES PATENT OFFICE presume MACHINE Application May 31, 1938, Serial No. 210,975 In Sweden June 10, 1937 3 Claims.

This invention relates to punching machines of the type commonly known as nibbling machines, that is to say, punching machines of the kind employed for cutting plate metal into pieces of any desired form, as, for instance, models for shoe making and the like, by a continuous punching operation along a given contour in which a small bit only of the plate metal is removed on each working stroke of the punch. The invention relates more particularly to nibbling machines used for cutting out pieces from a plate metal material of high resistance and of rather great thickness as compared with the diameter of the punch.

In the hitherto known machines of this type the upper end of the punch is firmly clamped into an upwardly and downwardly movable rod or slide. In order to prevent the cutting edge of the punch from contacting with the cutting edge of the die, the punch when clamped in its actuating member should be in exact alinement with the boring of the die. This alinement is also required because it is desired, as a rule, to effect the nibbling operation substantially without the formation of burr. This result, however, is very difficult to obtain in connection with well-known nibbling machines, especially in case of thin punches, because it often happens that the punch when in operation is bent to the side so that it strikes the edge of the hole, resulting in a damage of the punch or the die, or both.

The present invention has for its object to overcome said difliculty or reduce it so that it will be of no importance. To this end the punch is guided along a substantial portion of its length by a sleeve firmly clamped to the frame of the machine and which is in alinement with the die while the upper end of the punch is attached to its vertically reciprocable actuating member by connecting means which allow said end to adjust itself automatically into alinement with the portion of the punch in engagement with the guiding sleeve.

In the accompanying drawing one embodiment of the invention is illustrated. Fig. l is a front elevation of that part of the nibbling machine to which this invention relates. Fig. 2 is a vertical section at right angles to Fig. 1. Fig. 3 is a side elevation, partly in section, of the punch and its guidingv sleeve on a larger scale. Fig. 4 is a vertical section at right angles to Fig. 3. Fig. 5 is a plan view, with parts shown in section, of the guiding sleeve and its clamping device.

With reference to Figs. 1 and 2 the numeral I denotes the punch of the nibbling machine.

Numeral 2 designates an upwardly and downwardly movable slide in which the punch is clamped, 3 the clamping device proper, 4 an eccentric for operating the slide 2, 5 a guideway for the slide, and 6 an overhanging arm supporting 5 the above mentioned elements.

The clamping device comprises a horizontal journal 3 which is slidably and rotatably mounted in a transversely extending bore in the slide 2 into which it may be inserted and from which it may 10 be removed by means of a knob l. The punch is carried by the journal 3 by means of a pin 8 mounted to turn and slide in a transversely extending hole in the journal which is in its turn formed with a diametrically extending hole to 5 receive the upper end of the punch which is held in place in engagement with said hole by a set screw 9, as shown in Fig. 4. This mounting allows the punch to move in various ways, i. e. to turn into various angular positions and to move trans- 20 latorily in a plane perpendicular to the direction of movement of the punch.

The punch is guided by means of a guiding sleeve Ill which is jammed between a pair of clamping bars II and 12 secured to the overhanging arm 6 at the lower edge thereof by means of screws l3 which form between themselves a vertically through-extending seat to receive the guiding sleeve, as is shown in Fig. 5.

In Figs. 1 and 2 of the drawing there is shown, below the overhanging arm 6, a table or frame portion I4 carrying a die 15 which is adapted to support the material to be nibbled, and said die is formed in the usual way with a hole to receive the operating end of the punch after it has penetrated the material to be nibbled. The guiding sleeve Ii! extends nearly down to the die 15, the distance between the lower end of the sleeve l0 and the top surface of the die corresponding merely to the thickness of the material under operation. After unscrewing the screws [3 the sleeve Ill may be adjusted vertically in accordance with variation of the thickness of said material.

The seats formed in the stationary clamping bars I I and 12 are so designed that the boring of the sleeve, when the latter is clamped into the seats, is in exact alinement with the hole of the die, which result may be obtained in some wellknown way. When the sleeve lll is inserted into the seat of bar I2, it carries the punch and the associated journals 3 and 8, as shown in Figs. 3 and 4, the journal 3 being at the same time inserted into the respective boring of the slide 2. In clamping the guiding sleeve in the seat by mountpositively guided by the sleeve Ill almost down to the upper surface of the material to be cut, the exposed lower end of the punch will be very short and the risk of this end being bent will be obviated, so that the punch will under all conditions exactly enter the hole in the die after it has penetrated the plate material thereon. The guiding sleeve ll] forms an effective stripper on the upward stroke of the punch, thereby eliminating the need of a separate stripper.

- What I claim is:

1. In a nibbling machine, a frame, a stationary die in said frame, a stationary guiding sleeve mounted in the frame above the die, said frame having a stationary guideway parallel with said sleeve, a slide reciprocably mounted in said guideway, a punch in engagement with said guiding sleeve, and means to connect the upper end of said punch to said slide, said means comprising two journals at right angles to each other and to the punch, one of said journals being slidably and rotatably mounted in the slide and the other journal being slidably and rotatably mounted in said first-mentioned journal.

2. In a nibbling machine, a frame, a die, a vertically reciprocable slide, a punch, a stationary guiding sleeve for said punch secured to the frame above said die, and means to connect the upper end of the punch to the slide, said means comprising two journals at right angles to each other and to the slide, one of said journals being slidably and rotatably mounted in the slide and the other journal being slidably and rotatably mounted in the said first-mentioned journal.

3. In a nibbling machine, a frame, a stationary die in said frame, a stationary guideway in said frame, a slide reciprocably mounted in said guideway, a punch, means to connect the upper end of said punch to said slide with free lateral movement so as to allow said upper end to automati- HILMER GUSTAF ADOLF AKERLIND. 

